<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>return_book</title>
</head>
<style>

#return_book{
position:absolute;
left:30%;
top:30%;
}

#tip{
position:absolute;
left:30%;
top:40%;

}

</style>
<body>
<div id="return_book">
书籍ID:<input type="text" id='id' placeholder="书籍ID" required/>&nbsp;
<button id='return' onClick="return_book()">还书</button>
</div>
<div id="tip">

</div>

</body>
</html>